| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress increase in a noise level caused by a composite sound generated by overlap of carrier frequencies in performing carrier frequency diffusion control of a plurality of inverters. <P>SOLUTION: An inverter control device sets execution carrier frequencies f1* and f2* by using frequencies fset12 and fset22, which are twice as wide as frequencies fset11 and fset21, as diffusion frequencies fspr1 and fspr2 in the case that the extent of overlap between carrier frequency ranges fext1 and fext2 is equal to or more than a predetermined range, taking usually used frequencies fset11 and fset21 for the diffusion frequencies fspr1 and fspr2 (S140); and performs on and off control of a switching element of an inverter by pulse width modulation control using modulation waves of the execution carrier frequencies f1* and f2*. Thereby, even when a composite sound of electromagnetic sounds is generated, increase in a noise level can be suppressed by reducing the noise level of the composite sound. <P>COPYRIGHT: (C)2012,JPO&INPIT |
